[PUBDEV-2645] Flatfile mode fix
[PUBDEV-2645] Flatfile mode fix

After discussion with Tomas we fixed flatfile mode which was failing in Sparkling Water.

jangorecki/h2o-3,michalkurka/h2o-3,michalkurka/h2o-3,YzPaul3/h2o-3,YzPaul3/h2o-3,jangorecki/h2o-3,h2oai/h2o-dev,spennihana/h2o-3,h2oai/h2o-3,spennihana/h2o-3,h2oai/h2o-3,YzPaul3/h2o-3,h2oai/h2o-dev,michalkurka/h2o-3,mathemage/h2o-3,h2oai/h2o-3,spennihana/h2o-3,YzPaul3/h2o-3,jangorecki/h2o-3,mathemage/h2o-3,michalkurka/h2o-3,mathemage/h2o-3,spennihana/h2o-3,michalkurka/h2o-3,h2oai/h2o-3,jangorecki/h2o-3,michalkurka/h2o-3,h2oai/h2o-dev,mathemage/h2o-3,h2oai/h2o-dev,mathemage/h2o-3,h2oai/h2o-3,h2oai/h2o-3,h2oai/h2o-dev,jangorecki/h2o-3,spennihana/h2o-3,h2oai/h2o-3,spennihana/h2o-3,h2oai/h2o-dev,mathemage/h2o-3,jangorecki/h2o-3,YzPaul3/h2o-3,spennihana/h2o-3,YzPaul3/h2o-3,YzPaul3/h2o-3,h2oai/h2o-3,h2oai/h2o-dev,michalkurka/h2o-3,mathemage/h2o-3,jangorecki/h2o-3